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A clay matka keeps water cool in May. An innovator in Rajkot, Gujarat, turned that idea into a fridge that needs no electricity, and the Honey Bee Network exists so that inventors like him get found, named and supported. Here is how it works, and the science inside three inventions recorded by India's National Innovation Foundation.
What is the Honey Bee Network?
According to Anil K. Gupta's profile, which names him its founder, the Honey Bee Network was founded in 1988-89, and he set up SRISTI in 1993 to support it. Gupta taught at IIM Ahmedabad from 1981 to 2017.
The Honey Bee Network is a group of innovators, farmers, scholars, policy makers, entrepreneurs and NGOs, as its About page puts it. The same page says the network has documented more than 1,00,000 ideas, innovations and traditional knowledge practices.
The name is a promise: a honey bee collects pollen without the flowers complaining, and connects flower to flower, says the network's origin story. Its About page sets out the rules: name the person whose knowledge is recorded, unless they prefer otherwise, and send a fair share of any benefit back to them. SRISTI adds that the network must speak to people in their own language.
What does the National Innovation Foundation do?
The National Innovation Foundation (NIF) - India was established in March 2000 with the support of the Department of Science and Technology. Gupta helped establish it and was its Executive Vice Chair from 2000 to 2018, his profile notes.
NIF says it has compiled over 3,75,000 technological ideas, innovations and traditional knowledge practices from more than 730 districts, though not all are unique, and has recognised 1145 grassroots innovators and school students at the national level (NIF).
How does Mitticool, the clay fridge, keep food cool?
Mansukhbhai Prajapati of Rajkot made Mitticool entirely from clay. NIF's Mitticool page explains the principle: water from the upper chamber drips down the sides and evaporates, taking heat away from the inside. NIF lists it as keeping the inside 5-8 °C below the outside temperature, and keeping fruit, vegetables and milk fresh for 2 to 3 days.
Why does evaporation cool? A molecule escaping a liquid takes energy from what surrounds it. Water at 25 °C needs 2441.7 kJ per kilogram to evaporate, according to this table of water's heat of vaporisation.
NIF says Mitticool works well in hot, dry weather and depends on outside humidity. Humid air slows evaporation, the same reason air coolers stop working in humid weather.
How did the Laxmi Asu machine save weavers' time?
Before a Pochampally silk saree is woven, its yarn is wound by hand, a step called asu. NIF's Laxmi Asu page says this takes about 9000 to-and-fro hand movements and 1-1.5 days per saree, work long done by women. C. Mallesham of Nalgonda built a machine with a microcontroller, a motor and a mechanism that switches the yarn from one spoke to another. It takes 1.5 hours per saree.
The science here is control: a repeated motion becomes a sequence the microcontroller follows. NIF lists four limit switches, sensors that tell a controller when a moving part reaches the end of its travel.
How does Appachan's tree climber grip the trunk?
M. J. Joseph, known as Appachan, a farmer from Kannur, built a climber of two metal loops, one per leg, fastened to the trunk with ropes (NIF). Raise one pedal a little and its grip loosens so you can move it up; then your weight rests on it. In physics terms, standing presses the rope and rubber pad harder against the trunk, and friction can be at most μ times that normal force, so more weight allows a firmer grip.
NIF says it cuts climbing time for a 40 m tree to 1-2 minutes from the traditional 4-5. Taking the middle of each range, that is about 0.44 m/s against 0.15 m/s, roughly three times faster.
How can you spot the science in an invention near you?
Ask four questions of any jugaad you see:
What drudgery does it remove?
Where does the energy come from? (Evaporation, a motor, your own weight.)
What can you measure before and after? (Temperature, time, movements.)
What limits it? (Humidity for Mitticool; NIF says the climber fits trees 15-32 cm across.)
If latent heat or friction still feels abstract, the Fermi Concept Library has a lesson for every concept in physics, chemistry, biology, mathematics and computing. For ideas easier to see than read, try the interactive simulations in the Fermi Simulation Lab.
Have an idea? NIF's submit-an-idea page takes entries, and students in classes VI to X can be nominated through their schools for INSPIRE-MANAK. Next, read about Barefoot College and the solar engineers of Tilonia.
